There are two wifi connections. One allows the user to make up the connection name and make a password — this is the Hotspot. The other is used for wireless Android Auto and as far as I can tell we can't play with that, the Bluetooth connection handles the wifi connection in the background.
I don't recall step by step, it's been a while, but I recall it was in the settings menu and fairly apparent. But I found the other wifi first and wasted a bit of time before being out and finding the hotspot.